diff --git a/validate.hpp b/validate.hpp
index e2f9fe0..ad0700b 100644
--- a/validate.hpp
+++ b/validate.hpp
@@ -8,30 +8,29 @@ using std::to_string;
 
 
 vector<int> validate(vector<int> sequence, vector<int> guess) {
-	int S = sequence.size();
+	int N = sequence.size();
 
 	// Return values
 	int r_correct = 0;
 	int r_somewhere = 0;
 
 	// Find and remove correct values
-	for(int i = 0; i < S; i++) {
+	for(int i = 0; i < N; i++) {
 		if(sequence[i] == guess[i]) {
 			r_correct++;
-			sequence.erase(sequence.begin()+i);
-			guess.erase(guess.begin()+i);
-			i--;
-			S--;
+			sequence[i] = -1;
+			guess[i] = -1;
 		}
 	}
 
 	// Find values that are there somewhere
 	for(int col : guess) {
-		for(int i = 0; i < S; i++) {
+		if(col == -1)
+			continue;
+		for(int i = 0; i < N; i++) {
 			if(sequence[i] == col) {
 				r_somewhere++;
-				sequence.erase(sequence.begin()+i);
-				S--;
+				sequence[i] = -1;
 				break;
 			}
 		}